This invention relates to the recording and playing back of a video stream. A video stream includes any combination of audio and/or video data streams.
Video streams have typically been recorded on analog media such as a video cassette. A video cassette recorder (VCR) is used to record the video stream on the video cassette. The video stream may arrive via a broadcast signal, via cable, via satellite signal, or from another video playback device. Once the video stream has been recorded, the VCR is used to rewind the recording medium and play what was recorded. However, due to the nature of the analog medium, once the VCR has started recording, it is not possible to play back the portion of the video stream that has already been recorded until the recording session is terminated.
As a result of the inadequacies of analog VCR recording techniques, broadcast pause and resume systems have been developed which use digital storage techniques and random access technology to enable any portion of a stored digital stream to be essentially simultaneously recorded and replayed. Such systems may use hard disk drive memories which alternately write to and read from the hard disk drive memory in successive cycles. As the information is being recorded, it is quickly ready for replay.
A user may watch a television program, record it as the user watches and may institute pause and replay functions in the course of both watching and recording the incoming video steam. This may all be done without interrupting the recording of the ongoing video stream. Thus, while the user is watching a replay played back from the stored video, the storage system continues to record the incoming video so that a continuous recording is available. The user can watch the program from beginning to end, pausing and replaying in the course of the programs without missing any of the program.
Such systems require relatively high capacity, high speed storage devices. Conventional storage systems using buffers may be utilized for this function. However, the faster the storage media, the more realistic the broadcast pause and resume system is in terms of essentially simultaneously recording and playing back video.
Thus, there is a need for better ways to record streaming video so that the information is rapidly available for replay.